1. Field of the invention
The present invention relates to a flexible tube for an endoscope, which is used by, for example, being inserted into a living body.
2. Description of the Prior Art
In endoscopic examination, a flexible tube of an insertion section of an endoscope (that is, a section of an endoscope to be inserted into a body cavity) is inserted deep into a body cavity, such as stomach, duodenum, small intestine or large intestine.
When the endoscope is inserted into a body cavity, a surface of the flexible tube of the endoscope comes to contact with bacteria (e.g., coli bacteria) resident in the body cavity, so that bacteria adhere on the surface of the flexible tube.
In order to make it possible to use the endoscope repeatedly for many patients, the bacteria adheared onto the flexible tube must be removed. Therefore, the endoscope after use is normally subjected to a high temperature sterilization treatment or a disinfection treatment (that uses a peroxide disinfectant solution).
However, in the medical site, there is a demand that a further countermeasure against bacteria, virus and the like should be taken in order to repeatedly use the endoscope more safely for many patients.
In view of the above, it is an object of the present invention to provide a flexible tube for an endoscope which has an excellent antibacterial property.
In order to achieve the above object, the present invention is directed to a flexible tube for an endoscope, comprising:
a flexible elongated structural body; and
an outer cover provided over the elongated structural body, the outer cover having an outer peripheral part, and at least the outer peripheral part of the outer cover being made of a material which contains elastic resin and plant extract having an antibacterial property.
In this flexible tube, the plant extract and the resin that constitutes the outer cover are inert with respect to each other. Therefore, according to the present invention described above, it is possible to provide a flexible tube for an endoscope that can not only exhibit excellent antibacterial property against bacteria and the like, but also sustain the antibacterial property over a long period of time.
In the present invention, it is preferred that the outer cover includes an inner layer and an outer layer provided around the inner layer, in which the outer layer forms the outer peripheral part of the outer cover.
Further, in the present invention, it is also preferred that the content of the plant extract in the material for the outer cover is 0.1 to 30% by weight.
Furthermore, in the present invention, it is also preferred that the resin is at least one selected from the group consisting of polyvinyl chloride, polyurethane elastomer, polyester elastomer, polyolefin elastomer, polyamide elastomer, polystyrene elastomer, fluorine-based elastomer, and fluororubber.
Moreover, in the present invention, it is also preferred that the plant extract is obtained from at least one plant selected from the group consisting of plants belonging to the order Ranunculales. In this case, it is preferred that the plants belong to Nymphaeaceae and Ranunculaceae of the order Ranunculales.
Another aspect of the present invention is directed to a flexible tube for an endoscope, comprising:
a flexible elongated structural body;
an outer cover provided over the elongated structural body, the outer cover having an outer periphery and being made of a material which contains elastic resin; and
a covering layer provided on the outer periphery of the outer cover, the covering layer being made of a material which contains plant extract having an antibacterial property.
In the present invention, it is preferred that the covering layer has a thickness of 0.01 to 0.25 mm.
Further, in the present invention, it is also preferred that the content of the plant extract in the material for the covering layer is 0.1 to 30% by weight.
These and other objects, structures and advantages of the present invention will be apparent more clearly from the following description of the invention based on the examples.